the problem is that when u remove the nvidia drivers.. the files in
/usr/lib/xorg/modules/ are removed... but if you reinstall the intel driver it will copy the files back again and everything will be fine! :)

(https://launchpad.net/~bumblebee i am now using bumblebee for using the nvidia card whenever i want, and it works very fine! :D )

if you want to try again to install bumblebee, first we have to remove any old crap you may still have installed:

Just another suggestion. I also have an Nvidia card, but Gnome-shell seems to be more responsive with the nouveau driver rather than the official Nvidia one. I actually see a considerable improvement in almost everything Gnome-shell does.